The present invention relates to a parking mechanism arrangement for a motor vehicle transmission having a housing and a shaft supported so that it can rotate in relation to the housing, a parking mechanism gear which is rotationally fixed to the shaft and comprises a parking mechanism tooth system, a parking mechanism pawl which is supported so that it can pivot about a pawl axis in relation to the housing and comprises a pawl tooth, which is capable of engaging in a tooth space of the parking mechanism tooth system in order to establish a locked position, and having an actuating mechanism which comprises an actuating element, which acts upon an actuating portion of the parking mechanism pawl, in order to pivot the parking mechanism pawl from a release position into the locked position.
Parking mechanism arrangements of this type are generally known. These serve in a motor vehicle transmission, especially in a motor vehicle automated transmission, to immobilise the vehicle. Here the shaft is preferably an output shaft of the transmission which is operatively connected directly to the driven wheels of the motor vehicle. In the locked position a rotation of the shaft is prevented, consequently precluding any possibility of the vehicle rolling away.
There are also many known actuating mechanisms. In one embodiment a draw-cone is supported so that it is axially displaceable on the housing, said draw-cone releasing the parking mechanism pawl when in a release position and being drawn between a portion of the housing and an actuating portion of the parking mechanism pawl in order to establish the locked position, so as to provide the parking mechanism pawl with a positively interlocking position in relation to the housing, in which its pawl tooth engages in the parking mechanism tooth system.
For situations in which the pawl tooth rests on a tooth of the parking mechanism tooth system during this actuation sequence, the actuating mechanism may be equipped with a so-called engaging spring, which is then tensioned so that the actuating element shifts the parking mechanism pawl into the locked position owing to the energy stored in the engaging spring as soon as the parking mechanism gear rotates.
Further known actuating mechanisms are embodied in the form of cam elements, which are fixed to a shaft arranged parallel to the pawl axis.
The actuating mechanism may have an interface to a manual gear lever in the interior of the motor vehicle, so that when the lever is shifted into a “P” position the parking mechanism is actuated. Another known approach, on the other hand, is to equip the actuating mechanism with actuators in order to provide a so-called “park-by-wire” parking mechanism system. The actuators may be hydraulic actuators, but they may also contain electromechanical actuators such as shift rollers or drums.
Parking mechanism arrangements are generally subject to tight constraints in terms of design space. Furthermore, in designing the parking mechanism arrangement care has to be taken to ensure that in the park position excessive forces are not introduced into the housing and/or into bearings of the shaft.
Against this background an object of the invention is to specify an improved parking mechanism arrangement for a motor vehicle transmission which will preferably satisfy or improve upon at least one of the aforementioned constraints.